Mechanical hoist for trucks



Aug. l2 1924.

A. T. scANNELL `MECHANICAL HOIST FOR TRUCKS Filed Nov. l5 1919 3 Sheets-Sheet 1 Aug. 12 1924. 1,504,515

' A. T. SCANNELL MECHANICAL HOIST FOR TRUCKS Filed Nov. 15 1919 3 Sheets-Sheet 2 A. T. SCANNELL .Aug. 12 1924. ,504`,55

MECHANICAL HOIST FOR TRUCKS Filed Nov. l5 1919 .'S Sheets-Sheet 3 Patented Aug. l2, 1924.

Uirsn ALBERT T. SCANNELL,

F CHICAGO, ILLINOIS.

MECHANICAL HOIST FOR TRUCKS.

Application filed November 1919.

To all w hom t may concern.:

. ticularly to hoists of the type adapted for use in raising the bodies of motor vehicles to dump the contents thereof, the power for operating the hoist being derived from the power plant of the vehicle on which it is y mounted, as in the construction embodied in Patent No. 1,307,154, issued to me J une 17th, 1919, the present invention being designed as an improvement on the hoist illustrated in said patent.

The objects and advantages of the present invention will become apparent from the following description taken in connection with the accompanying drawings wherein one embodiment of the invention is illustrated.

Figure 1 is a side elevation of a motor vehicle showing the impro-ved hoist mounted in operative position thereon.

Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1, the hoist being shown in front elevation with parts thereof broken away. -Y

Fig. 3 is a detail view partly in section showing the mounting of the ram of the hoist, a part of the power transmitting mechanism, and the mechanism 'for controlling the raising and lowering of the ram, and

Fig. 4 isa detail view of the combined ratchet and pawl and brake mechanism utilized in the present improvements for controlling the movements of the ram.

Referring more in detail to the drawings a motor truck is illustrated at 1 and may be of any of the preferred types, said .truck being provided with the usual frame 2, and a power shaft 3 which projects rearwardly from the power plant (not shown) of the vehicle. Mounted on the frame 2 of the vehicle is shown a tilting or dumping body 7 preferably pivoted at the rear of the frame, asshown at-8, whereby said body may be raised or tilted substantially as shown in dottedlines-in Fig. 1 to thereby discharge the'contents of the same.

The hoist is preferably mounted on the Serial No. 338,188.

france2 of the vehicle intermediate the forward end of the body 7 and the operators seat 9, said hoistv being shown mounted on a plurality of transverse channel beams 10, which latter are secured in any suitable manner to the vehicle frame 2. The hoist, as shown, comprises a plurality of upright channel `beams 11 bolted or otherwise secured at their lower ends to the transverse channel beams 10,v said channel beams 11 being mounted with their channels facing each other, the opening at the sides being closed by plates 11, so as to provide a housing substantially rectangular in cross section. Slidably mounted within the housing thus provided between the channel beams 11 is an I-beam 12 which carries at its lower end a suitable sprocket wheel 13, said sprocket wheel beingrsupported from the lower end of said beam 12 by means of a bracket 14 attached to the web of said beam.

Riveted, or otherwise securely attached to the web of the I-beam 12 at the other end or top thereof, is a suitable bifurcated bracketr 15, the groove or channel of which is designed to receive the transverse beam 16. `The bracket 15 is provided with a plurality of supporting or pivot pins 17 designed to extend through openings in the beam 16, the said openings being slightly larger than the pins 17 so as to permit of a slight rocking or oscillating movement of the beam 16 upon operation of the hoist, as and for the purposes to be hereinafter pointed out. Swiveled in any suitable manner from each end of the transverse beam 16 is a sheave or pulley 18, a cable 19 passing over each of these pulleys 1S, and one end of each of said cables being pivotallyV attached in any suitable manner as at 20 to the lower ends of the depending arms 21, which latter are rigidly secured to the front wall ofthe vehicle body 7. The other end of each of said cables 19 is attached to suitable arms or brackets 22, which are rigidly secured to one of the transverse channel'beams 10. From the construction just described, which is more clearly illustrated in Fig. 2 of the drawings, it will be apparent that upon the raising of the slidably mounted I-beam 12, the transverse beam 16 together with the pulleys 18 will likewise be raised and as a result thereof, the body 7, by reason of the cable arrangement just described, will be tilted on its pivots to a position as illustrated in Fig. 1.

Should the load be unequally divided beoro tween the cables `19 during this tilting of the body, the beam 16 will, by reason of its mounting as above described, rock or tilt to one side or the other and in this manner compensate 1n a measure for any unequal Y distribution of the load whilefat the same y being on one side of the body than the other.

These advantages, due to the ofi1 center supports for the beam 16, are not obtained in the constructions heretofore designed whereina single centrallydisposed pivotal support for the beam is provided and this for the reason that in these prior constructions the'lever arms orVV the distance between the pivot and the points kof load suspension are always equal.` In the presentrconstruction the'lever arm on the light side will always be of greater length than the one on the heavy side, resulting in a balancing or compensating action. j Y

` I, The mechanism for raising and lowering Y theIIY-beam 12, the mechanism for controlling Vits movements andalso the means whereby powerfor operating saidbeam may be derived Yfrom the power Aplant of the vehicle willnow be described. To one of the channel beams 11 within the channel thereof is securely anchored one end 23 of a suitable length of' sprocket chain 24. VFrom this point of attachment, which, as will be observed, is near the upper end of the housing provided by the channel beams 11, the

sprocket chain 24 extends downwardly within said Vhousing and over thesprocket wheel 13; carried at the lower end of the I-beam 12. Fromthis point the sprocket chain ex tends'up through the housing adjacent the bottom of the channel provided in the other channel beam 11, Vsaid chain, ata point substantially Opposite the point of attachment ofthe end 23 thereof, passingoutwardly between adjacent edges of the channel beams l11, as shown at 25 and'over Ya second sprocket Y wheel 26 mounted 1n juxtaposition to said beams 11 on `al suitable transverse shaft 27,

lthe other end of'said chainbeing anchored to one of the mounted thereon for rotation therewith a gear wheel-,31and `a sprocket wheel 32. The gear wheel 31 `is splined. to thev shaft 30 in such' wise as to be slidable thereon into and out of mesh with a gear 33 on the power shaft, so that a driving connection may be established betweenrthe power shaft 3 and the lcounter shaft 30. The gear wheel 31 is shifted into and out of mesh with the gear wheel 33 by means of the bell crank level' 34, link 35 and the pivoted operating lever 36. The bell crank lever is of the bifurcated type, the two depending arms thereof engaging the collar of the gear wheel 31 so that uponoscillation of said lever 34, the said gear 31 is shifted. The lever 34 is supported 1n proper position on a pivot pin carried by depending arms 37 which are riveted or otherwise securely attached to one of the transverse beams 10. The link 35 is pivotally connected to the free end of the horizontal portion of the bell crank lever 34 and at its other end to one end of the operating lever 36, which latter is pivoted on a suitable bracket 38 which is attached to one of the channel beams 11. It will be apparent from the mechanism just described that the gear wheel 31 may be shifted into and out of mesh with the gear wheel 33 by merely raising or lowering the operating lever 36.

A sprocket chain 39 connects the sprocket wheel 32 with a larger sprocket wheel 40 carried at one end of a shaft 41 supported on one side ofthe beams 11 by means of suitable brackets 42. A small sprocket wheel 43 is carried at the other end of the shaft 41 and connects by means of a second sprocket chain 45, with the large sprocket wheel 44 carried on one end of the shaft 27. Through this reduction gearing just described power is transmitted from the power shaft 3 of the vehicle to the shaft 27, which shaft, as above described, carries the small sprocket wheel 26, which is engaged by the chain 24, which in turn lifts the I-beam or ram.

Upon movement of the operating lever 36 in such wise as to effect the meshing of the gears 33 and 31, the counter shaft 30, together with the sprocket wheel 32, is rotated, the latter, through the medium of the chain 39, sprocket wheel 40, sprocket wheel 43, chain'45,sproeket wheel 44, sprocket wheel 26 and chain 24 causing the slidable post or I-beam 12 to be raised within the housing provided by the beams 11, in such wise as to tilt the body on its pivots, as above described, ,for the purpose. of dumping the contents thereof. Y

As the I-beam or post-12 is elevated, the sprocket-chain 24 is fed downwardly ofi' the sprocket wheel 26 and hangs loosely therebeneath adjacent one: side ofthe beams 11, this slack portion of the chain forming a loop by reason of the end thereof heilig attached to thefbracket 28. A defiector 28fl is carried at the outerend of the bracket 28 designed to strip the chain 24 from the sprocket.-

Mounted on the shaft 41 intermediate its ends. is aratchet wheel 46 engaged by a suitable pawl 47, which pawl is pivoted at 48 to a suitable bracket 49 carried by one of the beams 11 and may be manually withdrawn from engagement with the ratchet wheel 46 by means of the operating lever 50 and connecting link 51. A spring 52 normally tends to maintain the pawl 47 in engagement with the sprocket wheel 46 so as to preclude the possibility of the I-beam or post 12 dropping to its normalposition after it has been raised toi a certain position and the gear 33 thrown out of mesh. In short, the ratchet and pawl mechanism acts to maintain the post or I-beam 12 in its raisedpositio-n after the driving connection between the power shaft 3 and the counter shaft 30 has been disengaged, and functions as a safety device at all times.

As a further featurey of the present improvement, means is `also provided for automatically disconnecting the gears 31 and 33 upon the arrival of the. slidable post or beam 12 at a predetermined point in its upward travel so as to avoid the possibility of said post or beam being raised beyond a certain limit. The means just referred to is in the form of a releasing bar 53, which is slidably mounted in a suitable bracket 54 carried by one of the beams 11, said bar being provided with an inturned end or pin 55, which projects through a suitable slot 56 provided in the adjacent face of the beam 11 on which the bracket 54 is carried. The lower end 55 extends into the housing provided by the channel beams 11 far enough to be engaged by the end 57 of the stud or pin on which the sprocket wheel 13 is mounted at the lower end of the I-beam or post 12 so that, when the I-beam or post reaches a certain position in its upward travel, the end 57 of said stud will engagepthe bar 53, causing the same to be lifted. During this elevation of the bar 53 the head 58 engages the operating lever 36 and lifts it, thereby disengaging the gears 33 and 31 and preventing further elevation of the slidable post.

After the hoist has been o'iperated, as above described, to elevate or tilt the body about its pivots to dump the contents thereof, the I-beain or slidable post 12 may be lowered to its normal position by merely disengaging the pawl 47 from the ratchet wheel 46 through the agencies of the operating lever 50 and the connecting link 51 above described. The I-beam or sliding post 12 may be thus released from any of its various positions of elevation whereupon said beam will be returned to its normal or lowermost position by gravity. To `avoid a sudden dropping of the slidable post 12, together with the various elements of construction carried thereby, upon the release of the pawl 47, a brake is provided which is automatically operated upon the disengagement of the pawl 47 so that the return of the hoist to normal position may be controlled. The braking mechanism just reis provided with a suitable recess 602L de` signed to receive a lug 62 carried b-y the collar 63, which latter preferably forms an integral part of the pawl 47 and is designed to oscillate or rock back and forth therewith. In advance of the recess or depression 6()a provided in the upper or free end of the semi-circular shaped brake band 60, said band is provided with a lug or projection 6()b designed to contact or rest against the collar 63 of the pawl 47 when said band is in inoperative position and in this manner to maintain said band in proper position to be operated. The construction just described is more clearly illustrated in Fig. 4 of the drawings.

From the foregoing description it will be observed that each time the operating lever 50 is moved to disengage the pawl 47 from its cooperating ratchet wheel in order to permit of the slidable post returning to its normal or lowermost position, the lug 62 carried by the collar 63 of said pawl 47 will cooperate with the upper end of the brain band 60 in such wise as to move the same into engagement with the brake drum 50, the braking effect being at the control of the operator through the lever 50 so that the speed of return of the post may be accurately regulated. As soon as the lever 50 is released, the spring 52, it will be observed,

will automatically return the pawl 47 into engagement with its ratchet wheel and also release the brake band 59 therebj7 permitting 'it to return by gravity to its inoperative position, as shown in Fig. 4.

It is preferred to provide a housing for all of the hoisting mechanism, which lies above the transverse beams 10 and to this end the housing 64 is provided comprising end plates and front and rear plates, this housing showing in side elevation in Fig. 1 of the drawings, but being totally removed in Fig, 2 thereof in order to illustrate the various details of construction of the hoist. The width of the hoist housing 64 is preferably such as to lie between the lifting cables 19 in such wise as to leave said cables exposed on each side of said housing.

It will be obvious to those skilled in the art that various changes and modifications may be made in the construction herein described and illustrated and accordingly, it .is not desired to limit the inventionv to the Cil particular embodiment illustrated eXcept Where limitations appear inthe appended claims. Y Y

- That Iclaim is r-f Y l. In a hoist, a slidableVV ram, a beam loosely supported on two pivots carried by said ram at the top thereof, one of said pivots being disposed on each side of the longitudinal axis of said ram and the' load beingy supported from opposite ends of said beam, whereby the'latter may rock from one of said pivots to the other to provide a long orral'short lever arm on eitherrside of said longitudinal axis depending upon the distribution of the load between the opposite ends of said beam.

2. In a hoist, a slidable ram, and a cross beam carried thereby `and designed to support the load, said beam being mounted on plurality of supports, oneion each side of the longitudinal axis of said ram whereby the point of application of the liftingthrust limparted to said beam may be shifted to compensate for unequal distributions of the load.

3. A body hoist of motor vehicles, comprising a support adapted for mounting across the frame of a vehicle, a plurality of' channel beams mounted on said support anddisposed with their channels face to face so as to providev a housing, a ram. slidably mounted within said housing, means for connecting said ram with the bodyof said vehicle, aVV sprocket Awheel supported from the bottom of said rain, a sprocket chain anchored at one end to one of said beams withinsaid housing and engaging said wheel, a second sprocket wheel mounted exteriorly ofV said housing, said chain extendingbetween said beams and over said second sprocket wheel atfits other end, and meansfor driving said second sprocket wheel by means of power derived from the power plant of said vehicle, whereby said ram may be raised and loi 7ered within said housing.

4c. In a hoist for motor vehicles, a slidable ram, a-shaft carried by the latter near its lower end, a sprocket wheel mounted on said shaft, means coacting with said sprocket wheel for lifting said ram, operating mecha- Vnism for said means, and means mounted in the path of said shaft and adapted to be engaged by the latter for rendering said Vmechanism inoperative at a predetermined point in the upward travel of said ram.

5. In a hoist for a motor vehicle body, a slidable ram, connections between said ram and said body, driving mechanism for said ram, means at the control of the operator for rendering said driving mechanism operative to raise said ram, means for holding said ram in its elevated position, means at the control of the operator for releasing said holding means, and means rendered operative by such release for rct-arding the downward movement of said ram to its no1'- mal position.

G. In a hoist for a motor vehiclebody, a slidable ram, connections between said ram and said body, driving mechanism for said ram, means at the control of the operator for rendering said driving mechanism operative to raise said ram, pawl and ratchet wheel mechanism normally acting to prevent the return of said ram, a brake drum adj acent said ratchet wheel, a brake band therefor, means at the control of the operator for releasing said pawl to return said ram to normal, and means carried by said pawl for moving said brake band'into engagement with said drum uponnelease of said pawl to thereby retard thedownward movement of said ram.

In testimony whereof, I have subscribed my name.

ALBERT T. SCANNELL. 

